$re = '/(.*)(\bfirstname=rahman\b)(.*)(\blastname=mahmoodi\b)(.*)(\bcountry=canada\b)(.*)/';
$str = 'firstname=rahman, middlename=abdul, lastname=mahmoodi, country=australia
firstname=rahman, middlename=james, lastname=mahmoodi, country=canada
firstname=rahman, middlename=james, lastname=mahmoodi, country=new zealand';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php